Coprophilous Species Research Articles

THE BASIDIOMYCETES OF SKOKHOLM ISLAND XIV. STABILITY OF THE MYGOTA

SummaryA method of estimating the stability of fungal populations from suitable field records is described, applicable to the Basidiomycetes. When significant instability is found the method also allows one to estimate the rate of change involved, and over a sufficient period also changes in the rate of change, at least qualitatively. These methods have been applied to data on the Basidiomycetes of Skokholm Island, collected from 1947 to 1956 inclusive.It was found that the lignicolous species were increasing, but that there was no overall change for practicolous, pteridietal, or coprophilous species. Within the praticolous group, however, two families, Agaricacei and Lycoperdacei, were in decline, while three, Clavariacei, Tricholomatacei and Cortinariacei, were increasing. There was evidence also of a change in composition of the mycota in the lignicolous group and among praticolous Cortinariacei (which were mainly Stropharioidei). The fungi of the Armerietum, a small group, appeared to be rapidly increasing. Temporary fluctuations in numbers, not much less in magnitude than these overall changes, ha'd occurred also in the pteridietal species and in the praticolous Hygrophoracei and Rhodophyllacei. No adequate evidence was found that any of these changes were accelerating or decelerating during the period.The magnitudes of the rates of change observed, on a per species basis, were mostly less than 1 per cent per annum; but the Clavariacei had increased and the Lycoperdacei decreased at considerably greater rates, but these were both small groups. The general conclusion was that the Skokholm mycota is in a rather stable condition.

Viability of spores of some coprophilous species of Sordaria and Chaetomium

Viability of spores of some coprophilous species of Sordaria and Chaetomium

Ecology of the larger fungi

Species of the larger fungi have definable preferences for particular ranges of p H of the substrate. The majority favour acid conditions but a minority prefer alkaline reaction. Some genera also appear to have similar definable preferences. The ecology of coprophilous species depends very largely upon reaction of the medium. Most humicolous basidiomycetes require a high average water content in the substrate. Studies of two ecological changes suggest that this factor is of major importance. The autumnal maximum of fungal fructification reflects the only time of year when soil temperature, soil water, and the level of available nitrogen, are simultaneously sufficient. Ecology of the lignicolous fungi can be investigated in the field by correlated measurements of p H and ‘hardness’ in order to determine the particular type and stage of decay. Rotting wood generally undergoes a change from very acid to neutral reaction; bark provides approximately neutral conditions throughout.